1. Field of the Invention
The present invention relates to a suspension apparatus for small cars, and more particularly, to a suspension apparatus which can be used in rear-wheel drive, front-wheel drive, or all-wheel drive type small automobiles, so as to rapidly absorb shock or vibration transmitted from wheels by use of four shock-absorbing devices.
2. Description of the Related Art
In general, cars are transportation means using rotation of wheels, and may be classified into passenger cars, vans, small cars, trucks, buses, etc. The present invention deals with an improved suspension apparatus that is mounted in passenger cars and vans (hereinafter, referred to as “small cars”).
Small cars are classified into a rear-wheel drive type designed to achieve a propelling force by transmitting power to rear wheels, a front-wheel drive type designed to achieve a propelling force by transmitting power to front wheels, and an all-wheel drive type designed to achieve a propelling force by transmitting power to front and rear wheels. The suspension apparatus of the present invention is applicable to all the rear-wheel drive, front-wheel drive, and all-wheel drive type small cars.
The suspension apparatus comprises: a spring to absorb and alleviate vibration or shock transmitted from the road surface and tires during traveling; and a shock-absorber to restrict the proper oscillation of the spring so as to achieve excellent driving comfort. In small cars, a coil spring (hereinafter, referred to as a “spring”) is widely used as the spring of the suspension apparatus.
As well known, in particular, the suspension apparatus may be classified into a front suspension apparatus and a rear suspension apparatus, on the basis of the mounting position thereof. Some suspension apparatuses comprise only a spring, whereas the remaining suspension apparatuses comprise both a spring and a shock-absorber.
With the provision of the spring, the suspension apparatus can serve to elastically alleviate vibration or shock transmitted from wheels.
However, it should be noted that, although the spring has an advantage of efficiently absorbing heavy vibration or shock transmitted from wheels, the spring tends to generate residual vibration due to an elastic repulsive force thereof after absorption of the heavy vibration or shock.
Consequently, there is a problem in that the residual vibration, generated from the spring after absorption of shock, is directly transmitted to a car body, resulting in a deterioration of driving comfort.
For this reason, the shock-absorber is installed to the lateral side of the spring or inside the spring, for the purpose of removing the residual vibration of the spring. On the basis of structural characteristics thereof, the shock-absorber accomplishes the removal of vibration or shock via movement of a fluid.
The shock-absorber using the flow of a fluid, however, is adapted to absorb vibration or shock gradually, rather than to absorb vibration or shock in an instant. Therefore, the shock-absorber has a problem in that it requires a relatively long time to absorb the residual vibration generated from the spring.
In conclusion, when absorbing the residual vibration of the spring via the movement of a fluid, a somewhat lapse in time is inevitable according to the flow rate of the fluid, therefore a relatively long time is required to absorb the residual vibration. Accordingly, the above described shock-absorber is incapable of rapidly absorbing shock or vibration transmitted from the wheels.